What liabilities we could face without general liability insurance?

I coordinate field trips for homeschooled families in my community. We are a volunteer group on Facebook with 3 admins hosting events for roughly 150 families in total (maybe 10-50 people per event). We work out details with venues, collect money, and transfer the money to the venue on the day of events. We also post occasional event meetups at the local park, trampoline parks, arcades, etc. We are not a formed business or nonprofit. I have concerns about what liabilities we could face without general liability insurance. The other admins don't think we are at risk for any liability since we don't host events in our homes. What liability could we be open to in this situation? Is it advisable to form a non-profit and get liability insurance?